There are various types of vacuum pump for realizing a vacuum state by being attached to a vacuum chamber and performing pumping. One of the pumps is a getter pump which removes gas residual in a vacuum chamber by using a getter having sorbing characteristic to various gas molecules. There are an evaporable getter which is used by evaporating (sublimating) a metal getter material and a non-evaporable getter which does not require evaporation.
The non-evaporable getter has a type which is used by pulverizing alloy that sorbs gas molecules into a powder-state or a type which is used by compressing the powder-state getter material and molding it into a pill-state (tablet state), for example. Of the types, the latter one is mostly used.
As prior art documents related to the non-evaporable getter and the non-evaporable getter pump having the getter, there are Published Japanese Translation of PCT Application No. 2009-541586 (Patent Document 1) and Japanese Patent Laid-open No. 2004-202309 (Patent Document 2) as patent documents. Further, there is Bulletin of Institute of Industrial Technology of Ehime Prefecture No. 48, p 18-20 2010 as a non-patent document.